At a rally on Tuesday, Mr Trump attacked the suggestion that his campaign had colluded with Russia, telling his audience in West Virginia: “Where is the collusion? They are still looking for collusion, where is the collusion? Find some collusion. We want to find the collusion.”

Will Cohen talk to Mueller?

There is no confirmation that he will speak to the Russia inquiry which, under former FBI director Robert Mueller, is tasked with establishing whether the Trump campaign conspired with Russia to swing the election in Mr Trump’s favour.

The well-documented meeting at Trump Tower between Mr Trump’s son, Donald Trump Jr, and a Russian lawyer is a focus of the Mueller inquiry.

Russian intelligence officers have since been charged in absentia by the US authorities with hacking the DNC using malicious software.

Interviewed by MSNBC on Tuesday evening, Mr Davis said he did not know if Cohen had been approached by the Mueller inquiry but that his client had been “liberated” by admitting guilt.

“From this point on, you are going to see a liberated Michael Cohen speaking truth to power,” he said.

Why was hush money paid?

Porn star Stormy Daniels said she had been paid $ 130,000 (£101,000) by Cohen just days before the 2016 election to keep quiet about an affair she says she had a decade earlier with Mr Trump.

Cohen also recorded a conversation with Mr Trump two months before the election in which they discussed buying the rights to a kiss-and-tell story by former Playboy model Karen McDougal who says she had an affair with Mr Trump.